Image is appearing flat in render but fine in camera view
The top picture is fully rendered using cycles I guess while the bottom one is from solid view. You can use the principled shader with
Metallic: ~0,8
 Roughness : ~0.8
Anisotropic ~0.3
To achieve a similar effect. This is just an estimate you need to play around with it

The top picture looks more plastic like. Probably because you didn't use the Metallic. Also the white background is flattening it. You seem to have no light source but the surrounding and this creates no dramatic shadows like in the bottom picture

At least that'd what I could figure out from what you provided